I had a scat name Marina Mar who suffered from baldness on the ears and scratching. after many different kinds of tests my vet took a piece of her ear and had it biopsied. It turns out she had pemphigus aerolus. it's a disease that attacks the body's cells that makes new skin. it was so far advanced it was in her nail beds and it was very painful. that something that you might want to mention to the vet.